Locking devices

ABSTRACT

In a locking device for sheet metal plugs, plates and other opening closures of the type which are locked in place by imparting an impacting blow to the locking device, an aperture is positioned between the plate and locking device for receiving an unlocking tool for unlocking the device.

United States Patent Boyer 1 1 1 Dec. 19, 1972 I54] LOCKING'DEVICES 2,682,693 7/l954 Poupitch ..24/73 M.F v 2,000,851 5/l935 Knell ....220/27 X [72] inventor: Fred S. Boyer, 5638' N. Kostner, j 2,068 988 1/1937 Knell ..220/27 Chicago, Ill. 60646 v Primary Examiner.-Raphael H. Schwartz [22] F'led: g 1970 Att0rney--M0linare, Allegretti, Newitt and Witcoff 21 A l.No.:60896 l 1 pp 57] ABSTRACT j In a locking device for sheet metal plugs, plates and [52] US. Cl 38552222): other opening closures the type which are locked I place imparting an impacting blow to e cking [58] Field of Search ..220/25, 59, 27, 24, 3.8, 3.2; device, an aperture is positioned between the plate 24/73 MP and locking device for receiving an unlocking tool for unlocking the device. [56] References Cited 4 Claims, 4 Drawing Figures UNITED'STATES PATENTS Peters ..220/27 PATENTED 05c 19 I972 I NVENTOR. FRED s. BOVER BY mm LOCKING DEVICES BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to a locking device and, more particularly, to an improved locking device for sheet metal closures.

Sheet metal discs, plates or other covers are frequently employed for the closing of openings of various sheet or cast metal boxes. By way of example, such boxes and the openings to be closed may be the conduit holes of electrical junction boxes or the access openings to electrical terminals or mechanisms in appliances and the like. These discs or plates desirably employ some form of locking means which will facilitate the rapid and easy locking in place of the disc or plate. In addition, such locking means should preferably be inexpensive in construction. One desirable disc and locking means construction which is capable, by way of example, of closing various conduit openings in electrical junction boxes, is described in my US. Letters Pat. No. 3,366,267. Another desirable disc and locking means is shown in my copending applicathe second tab means In another preferred embodiment of the invention ture means.

These and other objects, features and advantages of the'present invention will be more clearly understood through a consideration of the following detailed which locks the disc or plate in place is capable of rapid v and easy manipulation and that a minimum of effort and time need be expended in this unlocking operation.

The present invention relates to a locking device which is capable of rapid unlocking with a minimum of effort and time. The locking device constructed in accordance with the principles of the invention is both capable of rapid and easy locking action as well as unlocking action. The locking device of the invention is preferably a captive fastener which is formed directly from a part of the plate, disc, cover or sheet-metal assembly. The locking device of the invention is both simple in construction and inexpensive to manufacture. In the locking device of the invention, a locking member is provided which, when in the locked position, presents a smooth and finished surface relative to the plate upon which it is mounted, yet is capable of readily accepting an unlocking tool for unlocking the locking member.

In a preferred locking device of the invention for attaching a plate to a structure, a locking member is formed integrally with the plate. The locking member includes first and second tab means and hinge means is associated with the locking member such that the locking member is rotatable about the hinge means between a first unlocked position and a second locked position. In the first unlocked position, both of the tab means are angularly spaced from the opposite sides of the plate and the locking member is unlocked from the structure. In the second locked position, the structure is locked between one side of the plate and the first tab means and the second tab means is positioned adjacent and substantially parallel to the other side of the plate. Aperture means is defined between the second tab means and the plate for receiving an unlocking tool to effect rotation of the locking member from the locked position to unlock the member from the structure.

In one preferred embodiment of the invention, the plate is notched adjacent the second tab means to form the aperture means.

description.

BRIEF DESCRIPTION OF THE DRAWING In the course of this description, reference will frequentlybe made to the attached drawing in which: FIG. 1 is a plan view of a closure disc showing one preferred embodiment of locking device of the invention; I

FIG. 2 is a cross sectioned elevation view of a portion of the closure disc taken along line 2-2 of FIG. 1 and showing the locking member in the unlocked'and DESCRIPTION OF THE PREFERRED EMBODIMENTS One preferred embodiment of closure locking device which is constructed in accordance with the principles of the invention is shown in FIGS. 1-3 and a second preferred embodiment is shown in FIG. 4. The closure of each embodiment comprises a disc or plate member 10 which may be stamped or formed in any other suitable manner, from sheet metal or the like. The plate or disc may be such as is employed, for example, in the closure of electrical junction boxes as described in the above-mentioned earlier patent. One or more hinged locking members, generally 12, are formed in spaced relationship from each other about the perimeter of the disc,'preferably by way of stamping. Where only a single locking member is to be formed on the disc, a stationary unhinged hook tab 13, as shown in FIG. 1, is preferably formed on the plate or disc in spaced relation to the locking member 12 by stamping or the like to insure that the disc will be firmly retained in the opening. It will be understood that more than one of the locking members 12 and/or tabs 13 may be formed on any given disc as desired. Where the disc is to be of relatively large area, several members 12 and/or tabs 13 are preferred.

The locking member 12 is formed by a pair of tabs, a first tab 14 which extends downward at an angle from one side of the disc and a second tab 16 which extends upward at an angle from the other side of the disc. Both tabs 14 and 16 are preferably formed by simultaneously punching or stamping them from the disc sheet material. Upon stamping, an opening 18 is formed in the disc by the removal of tab 16. This opening is then preferably recessed at 20 about its periphery so as to form a downward extending bead 22 about the opening. This manner of construction provides a recess 20 in which the tab 16 of the locking member will readily be received in flush accommodation with the outer surface 23 of the disc 10 when the locking member is itself is notchedto form the aperlocked as shown in the solid lines in FIG. 2. If the tab16 was simply stamped from thesheet material of the disc, either the opening 18 would have to be somewhat enlarged or the tab 16 would have to be reduced in size, since stamping tends to enlarge the tab 16 such that it will not refit properly back into the opening. after stamping. By recessing the edge of the opening, the tab 16 may be readily returned'to the recess in flush I relationship to the disc upon locking of the locking In use, the disc 10 is positioned, tab 14 first, in the opening. Since the locking member 12 is in the angular relation to the disc as shown in the dotand dash lines in FIG. 2, tab 14 will easily clearthe edge of the opening 26 of the-structure S. Once the disc 10 is positioned in overlying and closing relationship to the opening 26, tab 16 need only be tapped lightly with. a hammer or other impact instrument. Upon striking the tab 16, the

locking member 12 will pivot about the pivot axis of the hinge formed by the interconnecting portions 28 of the sheet material of the disc. Referring to FIG. 2, when the locking member is so rotated into its locked position as shown in solid, the edge of the opening 26 in the structure S will be firmly clamped between one side 25 of thedisc and the tab 14, and tab 16 will enter the recess 20 so as to be substantially flush and coplanar with the outer planar surface 23' of the disc.

It will be seen that'whe'n the locking member 12 is in the fully locked position .such that tab 16 is neatly received within recess 20, that difficulty in unlocking of the member 12 might be encountered. With tab 16 received in the recess, little room, if any is left for the insertion of a prying tool, such as a screwdriver 30, between the adjacent portions of the recess 20 and tab 16. The use of such tool for prying these latter mentioned components apart becomes particularly important where the sheet material which is employed in the construction of the disc is of relatively heavy gauge.

In order to facilitate the unlocking of the locking device, an aperture 32 has been provided between the disc and the tab 16. This aperture is adapted to'receive a prying tool, such as screwdriver 30, to facilitate the unlocking of the locking device. ln the embodiment shown in FIGS. 1-3, this aperture 32 is formed by notching the'bead 22 adjacent the edge of the opening 18 by an amount sufficient that the aperture 32 is exposed when the locking member is in the fully closed position and tab 16 is fully received in the recess 20. Thereby, as shown in FIG. 3, a screwdriver 30 or other prying instrument may be readily inserted between the disc. and tab 16 in the aperture 32 and the locking member 12 may be rotated about the pivot axis of its hinge 28 from its locked position shown in the dot and dash lines in FIG. 3 to unlock the locking device.

Another embodiment of locking device and aperture construction is shown in FIG. 4-in which an aperture 32' IS formed by grinding off or otherwise removing a portion of the tip of tab 16 at 34 to form the aperture 32', rather thanby enlarging the opening 18.

It should be understood that theembodiments of the present invention which have been describedare merely illustrative of a few of the applications of ,the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the'true spirit and scope of the invention.

What is claimed is: i

l. A locking device for attaching a plate member to a structure comprising: g

a plate member having a predetermined configuration, at least one locking member on and adjacent an edge of the plate member, said locking member including a first tab which extends from one side of the plate member when saidlocking member is in a first position and which is adapted to receive the material of the structure therebetween, and a second tab interconnected with said first tab and which extends from the other side' of the plate member when said locking member is in said first position, a

hinge means associated with said locking member for rotation of said locking member about apivot axis thereof, said hinge means comprising portions of said plate member interconnecting said plate member with said locking member, said portions having at least apart thereof positioned laterally outward from one of said first and second tabs in a direction substantially parallel to said pivot axis, said locking member being rotatable about the pivot axis of said hinge means independentlyof said configuration of said plate member between said first position wherein said first tab is unlocked from said structure to a second position wherein said second tab is substantially parallel to said plate member and said first tab is in locking engagement with the material of said structure and extends toward said edge of said .plate member, and

aperture means defined between said second tab means and said plate member for receiving a tool for effecting rotation of said locking member between said positions.

2. The device of claim 1 wherein said plate includes an opening therein for receiving said second tabmeans when said locking member is in said'second locking position and said aperture meansis defined between the edges of said second tab means and said opening.

' 3. The device of claim 1 wherein said aperture means comprises a notch in said plate.

4. The device of claim 1 wherein said aperture means 

1. A locking device for attaching a plate member to a structure comprising: a plate member having a predetermined configuration, at least one locking member on and adjacent an edge of the plate member, said locking member including a first tab which extends from one side of the plate member when said locking member is in a first position and which is adapted to receive the material of the structure therebetween, and a second tab interconnected with said first tab and which extends from the other side of the plate member when said locking member is in said first position, hinge means associated with said locking member for rotation of said locking member about a pivot axis thereof, said hinge means comprising portions of said plate member interconnecting said plate member with said locking member, said portions having at least a part thereof positioned laterally outward from one of said first and second tabs in a direction substantially parallel to said pivot axis, said locking member being rotatable about the pivot axis of said hinge means independently of said configuration of said plate member between said first position wherein said first tab is unlocked from said structure to a second position wherein said second tab is substantially parallel to said plate member and said first tab is in locking engagement with the material of said structure and extends toward said edge of said plate member, and aperture means defined between said second tab means and said plate member for receiving a tool for effecting rotation of said locking member between said positions.
 2. The device of claim 1 wherein said plate includes an opening therein for receiving said second tab means when said locking member is in said second locking position and said aperture means is defined between the edges of said second tab means and said opening.
 3. The device of claim 1 wherein said aperture means comprises a notch in said plate.
 4. The device of claim 1 wherein said aperture means comprises a notch in said second tab means. 